176 
R. Ruggles Gates. 
A much earlier record of a double wallflower has, however, 
since been found (Saunders, 1916c). There is a reference to it in an 
Arabic “ Book of Agriculture ” of the 12th Century, the statements 
in which are based on an earlier work probably written about 1073. 
As we shall see, the records show that doubling is by no means 
rare in wild species, so it is quite possible that a double wall¬ 
flower was taken into cultivation as such. Doubling appears to 
have occurred at least twice in cultivation. The older, fully double 
wallflower (Saunders, 1917) was wholly sterile like the double stocks. 
It appears to have originated only once as a sport, and have since 
been propagated by cuttings. The partial double is more recent 
in origin and shows grades of doubling forming a continuous 
series. This double form is therefore not in the same series with 
the full double, but represents an independent germinal change. 
Bateson and Miss Sutton (1919) have found greater irregularity 
in Begonia. A double monoecious 2 X single $ gave singles 
generally dominant, but segregation was irregular and transitional 
forms appeared. An average of 1 double in 32 was obtained, and 
back crosses were also irregular. B. Davisii from Peru crossed 
on common doubles gave only double. This single is believed to 
be genetically double on the £ side. 
The first double Dahlia is mentioned and figured in a work on 
the natural history of Mexico, published at Rome in 1651. 1 Hence 
it apparently did not originate in cultivation. There are a number 
of early American records of wild species with double flowers, some 
of which may be summarized here. In Saxi/raga Virginiensis we 
have found nine records of double flowers, as follows : (1) A double 
found near Hingham, Mass., in 1849. 2 (2) Asa Gray 3 found a 
double at Dawers, Mass., 1866, which continued so from year to 
year. (3) A specimen found on the Delaware River below Easton 
with extra petals. 4 This was apparently not fully double. (4) A 
wild double from Canaan, Conn., was reported by A. Gray. 6 It 
bore 70 or 80 flowers, all pure white and fully double, without 
stamens. This very ornamental plant was divided, and part of it 
cultivated in the Cambridge, Mass., Botanic Garden. (5) Two 
more specimens were found 6 on the banks of the Schuylkill, near 
» Gard. Chron.59 : 336, 1916. 
2 J. L. R., Amer. Nat. 2 : 610, 1869. 
3 Amer. Nat. 2: 484, 1869. 
* Porter, Thos. C„ Bot. Gazette 1 : 5, 1875. 
4 Amer. Nat. 11 ; 366, 1877. 
8 Martindale, I. C., Amer. Nat. 11 : 432, 1877. 
